The invention is related to apparatus for rotationally mounting rolls of material to a support structure, in particular apparatus for mounting rolls of paper or Mylar.RTM. film, in a printer/plotter.
Many materials are stored on and dispensed from rolls. The print media used by printer/plotters is often stored on a roll and is usually wrapped on a hollow spool or core. The core and print media are often the same width so that the ends of the core are flush with the ends of the print media. To enable the roll to be mounted to the printer/plotter, or other apparatus, a core adapter is often used. One type of core adapter includes plugs at each end coupled together by an elongate rod, typically threaded at each end, passing through the core and the plugs. The roll is then supported by the portions of the plugs extending past the ends of the core. This prior art approach is, however, cumbersome to use. Each time a new roll is to be used the old one must be removed, the plugs unthreaded and the rods removed. These actions require a large workspace--at least twice the length of the roll. Also, the prior art approach has a number of parts, some of which are small and subject to being misplaced.
When a material is dispensed from a roll, as it often is with commercially available printer/plotters, a braking force can be used to control the rotation of the roll to prevent it from free-wheeling and dispensing too much material. Braking forces also provide a tension on the material as it leaves the roll. The need to prevent free-wheeling of the paper roll and the need to provide the paper with an acceptable tension as it enters a printer/plotter are very important considerations in the design of printer/plotters. The designer of mounting structures for rolls of material is therefore confronted with the seemingly mutually exclusive criteria of application of a proper braking force, ease of use by persons with minimal training, long life and reasonable cost.